Thanks! I have had it 9 years. It was my first carry gun.. when I was 22 and weighed about a buck fiddy.. carried in a snapless quick draw crossdraw holster Needless to say it was a bit much to conceal.
Anyway, it is a 686. On the frame just below the serial number, it reads, "MOD 686-4."
I wonder if you're right about it being nickel instead of stainless, though. If it's nickel, Im surprised at the quality of the plating. There is NO evidence anywhere of any chipping. Where the top of the frame/barrel is matte, there is no noticeable transition between matte and shiny. This alone led me to believe that it's just polished, but reading around, most S&W's that look like this are nickel plated, and the polshed models aren't anywhere near this shiny.
It could be an aftermarket job, as the trigger and hammer have also been polished or plated. I have not seen this in any other pics of S&W plated or polished revolvers.